This dissertation focuses on the relationship between new American music and National Public Radio (NPR) during the 1970s and 1980s. NPR directly supported American experimental music, most often billed as "new music," through programming that both consolidated a tradition and extended it by commissioning new works. I address three exemplary broadcasts, proposing that public radio utilized existing historical narratives of musical experimentalism while simultaneously revising and strengthening those narratives. I demonstrate ways in which the shows themselves, as well as their planning phases and promotional materials, served to gather individuals and musical practices together, defining and constructing musical experimentalism in the process. Chapter 1 covers the importance of sonic experimentation in NPR's original Statement of Purposes, claiming that author William Siemering's attention to sound created a climate that was especially hospitable to musical and radiophonic experimentation. In Max Neuhaus's Radio Net (1977), NPR's very infrastructure became a musical instrument, showing the radical potential of NPR in its early days. Chapter 2 chronicles the production history of RadioVisions (1981) to establish the ways in which NPR's imaginary listeners were essential during its planning phase: in the conception of the show, in the grant proposal to the NEA, and in the show's content. I conclude that experimentalism's potential for imagining an NPR audience allowed "new music" to become "American experimental music" as the RadioVisions project moved through the infrastructure of NPR. Chapter 3 explores the cultural valences and authorities of the musical voices in RadioVisions's segments "Details at Eleven," "Shoptalk," and "The Oldest Instrument," as well as Schuller's hosting voice in the context of public radio broadcasting. Chapter 4 presents a history of the composition, production, and radio broadcast of Maritime Rites (1984). I argue that the differences between Maritime Rites and RadioVisions were, in part, representative of changes in NPR from 1981-85, particularly the role of the newly established Satellite Program Development Fund in supporting adventuresome programming. Maritime Rites served not only as a sonic documentation of the Eastern seaboard, but also as a sonic documentation of the landscape of improvisational experimental music in the mid-1980s, enhancing its fit on NPR as new music/radio documentary. Chapter 5 offers an analysis of the second segment of Maritime Rites, which featured Pauline Oliveros and her improvisation "Rattlesnake Mountain," as well as the voice of Karen MacLean (the only female lighthouse keeper in the series). This dissertation contributes to a deeper understanding of NPR's history by addressing lesser-known yet significant cultural programs, as well as to a broader musicological understanding of how public radio contributed to the construction of musical experimentalism.